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Chemistry · Glossary

What is Nodes?

Also known as: nodal surface · radial node · angular node

Definition 13.8 University Chemistry — Year 2 · Chapter 13 — Atomic Orbitals: Shapes, Energies and Sizes

A nodal surface of an orbital is a surface on which the wavefunction is zero and changes sign. It is a radial node (a sphere) when the radial part vanishes, an angular node (a plane or a cone through the nucleus) when the angular part does.

Left: radial distributions P(r) = r2R2 of the orbitals of hydrogen up to n = 3; the larger n, the farther the electron, and the s orbitals have small inner maxima (penetration). Right: R_2s and R_3s change sign at their radial nodes (r = 2a_0; 1.90a_0 and 7.10a_0). Left: radial distributions P(r) = r2R2 of the orbitals of hydrogen up to n = 3; the larger n, the farther the electron, and the s orbitals have small inner maxima (penetration). Right: R_2s and R_3s change sign at their radial nodes (r = 2a_0; 1.90a_0 and 7.10a_0).
Left: radial distributions P(r)=r2R2P(r) = r^2R^2 of the orbitals of hydrogen up to n=3n = 3; the larger nn, the farther the electron, and the s orbitals have small inner maxima (penetration). Right: R2sR_{2s} and R3sR_{3s} change sign at their radial nodes (r=2a0r = 2a_0; 1.90a01.90a_0 and 7.10a07.10a_0).
Dot-density pictures of the 1s and 2s orbitals of hydrogen in a plane through the nucleus: the density of dots follows | |2 (deterministic sampling). The 2s cloud has an empty ring, the radial node at 2a_0 (dashed); the frames are 12 and 28 a_0 wide. Dot-density pictures of the 1s and 2s orbitals of hydrogen in a plane through the nucleus: the density of dots follows | |2 (deterministic sampling). The 2s cloud has an empty ring, the radial node at 2a_0 (dashed); the frames are 12 and 28 a_0 wide.
Dot-density pictures of the 1s and 2s orbitals of hydrogen in a plane through the nucleus: the density of dots follows ∣ψ∣2|\psi|^2 (deterministic sampling). The 2s cloud has an empty ring, the radial node at 2a02a_0 (dashed); the frames are 12 and 28 a0a_0 wide.
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